Modified Flows 2020, Upper Snake River Basin

Total Page:16

File Type:pdf, Size:1020Kb

Modified Flows 2020, Upper Snake River Basin Technical Memorandum Modified Flows 2020, Upper Snake River Basin Columbia Pacific Northwest Region U.S. Department of the Interior October 2020 Mission Statements The Department of the Interior conserves and manages the Nation’s natural resources and cultural heritage for the benefit and enjoyment of the American people, provides scientific and other information about natural resources and natural hazards to address societal challenges and create opportunities for the American people, and honors the Nation’s trust responsibilities or special commitments to American Indians, Alaska Natives, and affiliated island communities to help them prosper. The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public. Table of Contents Acronyms and Abbreviations ........................................................................................... iii 1. Introduction .................................................................................................................. 1 1.1. Reclamation Modified Flows Process .........................................................................................1 1.2. Differences from Modified Flows 2010 .....................................................................................2 2. Unregulated Flow Dataset Development.................................................................. 4 2.1. Unregulated Flows Methodology.................................................................................................4 2.2. Groundwater ............................................................................................................................................5 2.3. Unregulated Flows in the Upper Snake ....................................................................................5 3. Modified Flow Dataset Development ....................................................................... 8 3.1. Reference RiverWare Model............................................................................................................8 3.2. Irrigation Demand Pattern ............................................................................................................ 12 3.3. Current Level of Groundwater Pumping and Return Flows ........................................ 15 3.4. Upper Snake River Operation ...................................................................................................... 17 3.5. 2020 Modified Flows in the Upper Snake............................................................................. 17 4. Discussion....................................................................................................................18 5. Summary .....................................................................................................................22 6. Literature Cited...........................................................................................................23 List of Figures Figure 1. Upper Snake River, including the Boise and Payette River basins ............................................. 3 Figure 2. Selected unregulated flows for the different gages in the Upper Snake on a daily (blue) and monthly (orange) time step ................................................................................ 6 Figure 3. Schematic of RiverWare representation of the Upper Snake River ........................................... 9 Figure 4. Schematic of RiverWare representation of the Boise and Payette Rivers ............................ 10 Figure 5. Schematic of RiverWare representation of Henrys Fork of the Upper Snake River........................................................................................................................................................... 11 Figure 6. Annual irrigation demand diversion patterns for the sum of all the water users for each of the subbasins (Boise (BOI), Payette (PAY) and Upper Snake (SNK)) that are repeated for every dry, average, and wet year in the model simulations ........................................................................................................................ 15 Modified Flows 2020 – Upper Snak e River Basin i Figure 7. The total annual groundwater pumping pattern removed as reach losses throughout the Upper Snake........................................................................................................... 16 Figure 8. 2020 Modified Flows data set for BRN for water years 1928 to 2018 ................................... 17 Figure 9. Total annual demand for the Snake, Boise, and Payette subbasins from 1994 to 2017 .......................................................................................................................................... 18 Figure 10. 2020 Modified Flows monthly data set compared with the 2010 Modified Flows data set for water years 1999 to 2018 ............................................................................. 20 Figure 11. 2020 Modified Flows daily data set compared with the actual flows at BRN for water years 2009 to 2018 ........................................................................................................... 21 List of Tables Table 1. Comparison of the Brownlee 2020 Unregulated Flows dataset to the 2010 Unregulated Flows dataset for years 1999 to 2008 (the last 10 years of overlap). All volumes are in acre-feet. ............................................................................................. 7 Table 2. Years used to create wet, average, and dry patterns for the different basins...................... 12 Table 3. Total annual demand for the dry, average, and wet year patterns used in modeling ................................................................................................................................................. 13 Table 4. Comparison of the 2020 Modified Flows dataset to the 2010 Modified Flows dataset for years 1999 to 2008 (the last 10 years of overlap). All volumes are in acre-feet. ..................................................................................................................................... 19 Table 5. Comparison of the 2020 Modified Flows dataset to measured inflows into Brownlee Dam (BRN) for years 2009 to 2018. All volumes are in acre- feet. ............................................................................................................................................................ 19 ii Modified Flows 2020 – Upper Deschutes Basin Acronyms and Abbreviations Acronym or Definition Abbreviation AF Acre-feet AMFI Snake River at Neeley American Falls Inflow ANDI South Fork Boise River at Anderson Ranch ANTI Henrys Fork at St. Anthony, Idaho ARKI Boise River Arrowrock Inflow BIGI Boise River at Glenwood Bridge near Boise, Idaho BFTI Snake River near Blackfoot, Idaho BLFI Blackfoot River near Blackfoot, Idaho BOI Boise River Subbasin BOMI Boise River near Middleton, ID BPA Bonneville Power Administration BRN Snake River at Brownlee Dam Inflow BSHI Blackfoot River near Shelley, Idaho BTSI Boise River near Twin Springs, Idaho (TwSp) Buhl Snake River near Buhl, Idaho cfs Cubic feet per second CHEI Falls River near Chester, Idaho Corps U.S. Army Corps of Engineers CSCI North Fork Payette River Cascade Dam Inflow DEDI Deadwood River Deadwood Reservoir Inflow DGGI Teton River above South Leigh Creek EMMI Payette River Black Canyon Reservoir Inflow FALI Falls River near Squirrel, Idaho GRS Grassy Lake Inflow HENI Henrys Lake Inflow HEII Snake River near Heise, Idaho HFAI Henrys Fork near Ashton, Idaho HRSI Payette River near Horseshoe Bend, Idaho IDWR Idaho Department of Water Resources ISLI Henrys Fork near Island Park, Idaho Island Park Inflow JCKY Jackson Lake Inflow Modified Flows 2020 – Upper Snake River Basin iii Acronym or Definition Abbreviation JKSY Snake River below Flat Creek near Jackson, Wyoming KIMI Snake River near Kimberly, Idaho LUCI Boise River Lucky Peak Inflow MILI Snake River at Milner, Idaho MINI Snake River near Minidoka, Idaho OWYI Lake Owyhee and Owyhee River near Nyssa, Oregon PABI North Fork Payette River near Banks, Idaho PALI Snake River near Irwin Palisades Inflow PARI Boise River near Parma, Idaho PAY Payette River Subbasin PAYI North Fork Payette River at McCall PLEI Payette River near Leatha, Idaho PRLI South Fork Payette River at Lowman, Idaho PRPI Payette River near Payette, Idaho Reclamation Bureau of Reclamation REXI Henrys Fork near Rexburg, Idaho RIRI Willow Creek below Ririe Dam Ririe Dam Inflow SHYI Snake River near Shelley, Idaho SKHI Snake River at King Hill, Idaho SNK Upper Snake River Subbasin SnkblwSalmon Snake River below Lower Salmon Falls near Hagerman, Idaho SWAI Snake River near Murphy, Idaho TEAI Teton River near St. Anthony, Idaho TRXI Teton River at mouth VALO Malheur River below Nevada Dam near Vale, Oregon (Malheur) WEII Snake River near Weiser, Idaho WFWI Willow Creek at mouth near Idaho Falls, Idaho WRCC Western Regional Climate Center iv Modified Flows 2020 – Upper Snake River Basin 1. Introduction Modified Flows, as computed by the Bureau of Reclamation (Reclamation), are the historical unregulated streamflows from 1928 through 2018 adjusted to reflect what would have occurred with 2020 level reservoir regulation and 2020 level demands. Reclamation produces these flows for the Deschutes, Upper Snake, and Yakima river systems and provides the data to Bonneville Power Administration (BPA) for use in Columbia
Recommended publications
  • National Register of Historic Places Registration Form
    NPS Form 10-900 OMB No. 10024-0018 (Oct. 1990) United States Department of the Interior ,C£$ PftRKSERVIC National Park Service National Register of Historic Places Registration Form This form is for use in nominating or requesting determinations for individual properties and districts. See instructions in How to Complete the National Register of Historic Pla Registration Form (National Register Bulletin 16A). Complete each item by marking "x" in the appropriate box or by entering the information requested. If an item does not ap property being documented, enter "N/A" for "not applicable." For functions, architectural classification, materials, and areas of significance, enter only categories and subcatei instructins. Place additional entries and narrative items on continuation sheets (NPS Form 10-900a). Use a typewriter, word processor, or computer, to complete all items. 1. Name of Property historic name: American Falls Reservoir Flooded Townsite other name/site number: 2. Location street & number American Falls Reservoir [ ] not for publication city or town American Falls ______ [ X ] vicinity state: Idaho code: ID county: Power code: 077 zip code: 83211 3. State/Federal Agency Certification As the designated authority under the National Historic Preservation Act, as amended, I hereby certify that this [X] nomination [ ] request for determination of eligibility meets the documentation standards for registering properties in the National Register of Historic Places and meets the procedural and professional requirements set forth in 36
    [Show full text]
  • Draft Environmental Impact Statement, Minidoka Dam Spillway
    Draft Environmental Impact Statement Minidoka Dam Spillway Replacement Minidoka Project, Idaho U.S. Department of the Interior Bureau of Reclamation Pacific Northwest Region Snake River Area Office Boise, Idaho December 2009 U.S. DEPARTMENT OF THE INTERIOR The mission of the Department of the Interior is to protect and provide access to our Nation’s natural and cultural heritage and honor our trust responsibilities to Indian tribes and our commitments to island communities. MISSION OF THE BUREAU OF RECLAMATION The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public. Draft Environmental Impact Statement Minidoka Dam Spillway Replacement Minidoka Project, Idaho U.S. Department of the Interior Bureau of Reclamation Pacific Northwest Region Snake River Area Office Boise, Idaho December 2009 Draft Environmental Impact Statement Minidoka Dam Spillway Replacement Minidoka County, Idaho Lead Agency: For further information contact: U.S. Department of the Interior Allyn Meuleman Bureau of Reclamation Snake River Area Office Pacific Northwest Region 230 Collins Road Boise, ID 83702-4520 (208) 383-2258 Cooperating Agency: U.S. Department of the Interior U.S. Fish and Wildlife Service Idaho Fish and Wildlife Office Abstract: This Draft Environmental Impact Statement (Draft EIS) examines alternatives to correcting structural problems at the Minidoka Dam Spillway and associated facilities on Lake Walcott, Idaho. Alternatives considered in the Draft EIS are the No Action, as required under the National Environmental Policy Act; total replacement of the spillway and headgate structures; and replacement of just the spillway.
    [Show full text]
  • Snake River Flow Augmentation Impact Analysis Appendix
    SNAKE RIVER FLOW AUGMENTATION IMPACT ANALYSIS APPENDIX Prepared for the U.S. Army Corps of Engineers Walla Walla District’s Lower Snake River Juvenile Salmon Migration Feasibility Study and Environmental Impact Statement United States Department of the Interior Bureau of Reclamation Pacific Northwest Region Boise, Idaho February 1999 Acronyms and Abbreviations (Includes some common acronyms and abbreviations that may not appear in this document) 1427i A scenario in this analysis that provides up to 1,427,000 acre-feet of flow augmentation with large drawdown of Reclamation reservoirs. 1427r A scenario in this analysis that provides up to 1,427,000 acre-feet of flow augmentation with reservoir elevations maintained near current levels. BA Biological assessment BEA Bureau of Economic Analysis (U.S. Department of Commerce) BETTER Box Exchange Transport Temperature Ecology Reservoir (a water quality model) BIA Bureau of Indian Affairs BID Burley Irrigation District BIOP Biological opinion BLM Bureau of Land Management B.P. Before present BPA Bonneville Power Administration CES Conservation Extension Service cfs Cubic feet per second Corps U.S. Army Corps of Engineers CRFMP Columbia River Fish Mitigation Program CRP Conservation Reserve Program CVPIA Central Valley Project Improvement Act CWA Clean Water Act DO Dissolved Oxygen Acronyms and Abbreviations (Includes some common acronyms and abbreviations that may not appear in this document) DREW Drawdown Regional Economic Workgroup DDT Dichlorodiphenyltrichloroethane EIS Environmental Impact Statement EP Effective Precipitation EPA Environmental Protection Agency ESA Endangered Species Act ETAW Evapotranspiration of Applied Water FCRPS Federal Columbia River Power System FERC Federal Energy Regulatory Commission FIRE Finance, investment, and real estate HCNRA Hells Canyon National Recreation Area HUC Hydrologic unit code I.C.
    [Show full text]
  • Assessment of Fisheries Losses in the Upper Snake River Basin in Idaho Attributable to Construction and Operation of Dams with Federal Hydropower Facilities
    ASSESSMENT OF FISHERIES LOSSES IN THE UPPER SNAKE RIVER BASIN IN IDAHO ATTRIBUTABLE TO CONSTRUCTION AND OPERATION OF DAMS WITH FEDERAL HYDROPOWER FACILITIES Idaho Department of Fish and Game IDFG Report Number 07-52 August 2007 ASSESSMENT OF FISHERIES LOSSES IN THE UPPER SNAKE RIVER BASIN IN IDAHO ATTRIBUTABLE TO CONSTRUCTION AND OPERATION OF DAMS WITH FEDERAL HYDROPOWER FACILITIES Prepared by: Idaho Department of Fish and Game 600 South Walnut Street P.O. Box 25 Boise, ID 83707 IDFG Report Number 07-52 August 2007 TABLE OF CONTENTS Page ASSESSMENT OF FISHERIES LOSSES IN THE UPPER SNAKE RIVER BASIN IN IDAHO ATTRIBUTABLE TO CONSTRUCTION AND OPERATION OF DAMS WITH FEDERAL HYDROPOWER FACILITIES................................................................................ 1 ABSTRACT................................................................................................................................... 1 INTRODUCTION .......................................................................................................................... 2 BACKGROUND AND DESCRIPTION OF STUDY AREAS.......................................................... 2 Anderson Ranch Dam and Reservoir ........................................................................................ 2 Black Canyon Dam and Reservoir............................................................................................. 3 Deadwood Dam and Reservoir.................................................................................................. 4 Boise River Diversion
    [Show full text]
  • Minidoka Project Reservoirs Store Flow of the Snake Snake the of Flow Store Reservoirs Project Minidoka Many Benefits Benefits Many
    September 2010 2010 September 0461 0461 - 678 (208) Office Field Snake Upper www.usbr.gov/pn the American public. public. American the economically sound manner in the interest of of interest the in manner sound economically related resources in an environmentally and and environmentally an in resources related develop, and protect water and and water protect and develop, clamation is to manage, manage, to is clamation Re of The mission of the Bureau Bureau the of mission The Recreation: over 674,000 visits - $25 million million $25 - visits 674,000 over Recreation: Flood damage prevented: $8.8 million million $8.8 prevented: damage Flood Power generated: $5.6 million million $5.6 generated: Power Livestock industry: $342 million million $342 industry: Livestock IDAHO–WYOMING IDAHO–WYOMING Irrigated crops: $622 million million $622 crops: Irrigated What’s the Yearly Value? Value? Yearly the What’s Project Project the West. West. the Minidoka Minidoka some of the best outdoor recreation opportunities in in opportunities recreation outdoor best the of some also provides fish and wildlife enhancement and and enhancement wildlife and fish provides also The Story of the the of Story The production, and to reduce flood damage. The project project The damage. flood reduce to and production, River system for later irrigation use, electricity electricity use, irrigation later for system River Minidoka Project reservoirs store flow of the Snake Snake the of flow store reservoirs Project Minidoka Many Benefits Benefits Many Congress passed the Reclamation Act in 1902 to storing project water. The 1911 permanent dam was Railroad Draws Settlers bring water to the arid West.
    [Show full text]
  • Evaluation of Seepage and Discharge Uncertainty in the Middle Snake River, Southwestern Idaho
    Prepared in cooperation with the State of Idaho, Idaho Power Company, and the Idaho Department of Water Resources Evaluation of Seepage and Discharge Uncertainty in the Middle Snake River, Southwestern Idaho Scientific Investigations Report 2014–5091 U.S. Department of the Interior U.S. Geological Survey Cover: Streamgage operated by Idaho Power Company on the Snake River below Swan Falls Dam near Murphy, Idaho (13172500), looking downstream. Photograph taken by Molly Wood, U.S. Geological Survey, March 15, 2010. Evaluation of Seepage and Discharge Uncertainty in the Middle Snake River, Southwestern Idaho By Molly S. Wood, Marshall L. Williams, David M. Evetts, and Peter J. Vidmar Prepared in cooperation with the State of Idaho, Idaho Power Company, and the Idaho Department of Water Resources Scientific-Investigations Report 2014–5091 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior SALLY JEWELL, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director U.S. Geological Survey, Reston, Virginia: 2014 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1–888–ASK–USGS For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text.
    [Show full text]
  • (E.1-2) Geomorphology of the Hells Canyon Reach of the Snake River
    Geomorphology of the Hells Canyon Reach of the Snake River Steve Miller, CH2M HILL Dick Glanzman, CH2M HILL Sherrill Doran, CH2M HILL Shaun Parkinson, Idaho Power Company John Buffington, University of Idaho and Jim Milligan, University of Idaho (Ret.) Technical Report Appendix E.1-2 May 2002 Revised July 2003 Hells Canyon Complex FERC No. 1971 Copyright © 2003 by Idaho Power Company Idaho Power Company Geomorphology of the Snake River Basin and Hells Canyon CONTENTS Chapter Page Definitions...................................................................................................................................... xi Acronyms.................................................................................................................................... xvii Executive Summary.....................................................................................................................C-1 Preface..........................................................................................................................................C-5 1. Introduction and Geologic and Geomorphic History............................................................... 1-1 1.1. Introduction ...................................................................................................................... 1-2 1.2. Current Physiographic Description .................................................................................. 1-3 1.3. Pre-Quaternary Geologic History....................................................................................
    [Show full text]
  • National Register of Historic Places Registration Form
    OMB No. 10024-0018 United States Department of the Interior National Park Service National Register of Historic Places Registration Form This form is for use in nominating or requesting determinations of eligibility for individual properties or districts See instructions iQf_K WCc$)p/4HUU National Register of Historic Places Form (National Register Bulletin 16A). Complete each item by marking "x" in the a\ propriate bo:i)| or by entering the information requested. If an item does not apply to the property being documented, enter "N/A" for "not applicable." For functions, archi ectural class!sijfication, materials, and areas of significance, enter only categories and subcategories from the instructions. Place additional entries and narrative items on ontinuation sfte,ets (^I=S Form 10-9003).. Use a typewriter, word processor, or computer to complete all items. NATIONAL REGiSl i KsbTOHY 1. Name of Property & EDUCATION NATIONAL PARK SERVICE historic name Rupert Town Square Historic District other names/site number N/A 2. Location street & number Roughly bounded by 7th Street. E Street. 5th Street, and F Street________ N/A not for publication city or town Rupert_____________________________ N/A vicinity state Idaho code ID county Minidoka______________ code 067 zip code 83301 3. State/Federal Agency Certification As the designated authority under the National Historic Preservation Act, as amended, I hereby certify that this _X nomination _request for determination of eligibility meets the documentation standards for registering properties in the National Register of Historic Places and meets the procedural and professional requirements set forth in 36 CFR Part 60. In my opinion, the property _X_meets _does not meet the National Register criteria.
    [Show full text]
  • Historic Resource Study: Minidoka Interment Internment National
    Historic Resource Study Minidoka Internment National Monument _____________________________________________________ Prepared for the National Park Service U.S. Department of the Interior Seattle, Washington Minidoka Internment National Monument Historic Resource Study Amy Lowe Meger History Department Colorado State University National Park Service U.S. Department of the Interior Seattle, Washington 2005 Table of Contents Acknowledgements…………………………………………………………………… i Note on Terminology………………………………………….…………………..…. ii List of Figures ………………………………………………………………………. iii Part One - Before World War II Chapter One - Introduction - Minidoka Internment National Monument …………... 1 Chapter Two - Life on the Margins - History of Early Idaho………………………… 5 Chapter Three - Gardening in a Desert - Settlement and Development……………… 21 Chapter Four - Legalized Discrimination - Nikkei Before World War II……………. 37 Part Two - World War II Chapter Five- Outcry for Relocation - World War II in America ………….…..…… 65 Chapter Six - A Dust Covered Pseudo City - Camp Construction……………………. 87 Chapter Seven - Camp Minidoka - Evacuation, Relocation, and Incarceration ………105 Part Three - After World War II Chapter Eight - Farm in a Day- Settlement and Development Resume……………… 153 Chapter Nine - Conclusion- Commemoration and Memory………………………….. 163 Appendixes ………………………………………………………………………… 173 Bibliography…………………………………………………………………………. 181 Cover: Nikkei working on canal drop at Minidoka, date and photographer unknown, circa 1943. (Minidoka Manuscript Collection, Hagerman Fossil
    [Show full text]
  • Minidoka County, Idaho, Wildland-Urban Interface Wildfire Mitigation Plan Mmmaaaiiinnn Dddooocccuuummmeeennnttt Oooccctttooobbbeeerrr 111888,,, 222000000444
    Minidoka County, Idaho, Wildland-Urban Interface Wildfire Mitigation Plan MMMaaaiiinnn DDDooocccuuummmeeennnttt OOOccctttooobbbeeerrr 111888,,, 222000000444 Vision: Institutionalize and promote a countywide wildfire hazard mitigation ethic through leadership, professionalism, and excellence, leading the way to a safe, sustainable Minidoka County. This plan was developed by the Minidoka County Wildland-Urban Interface Wildfire Mitigation Plan Committee in cooperation with Northwest Management, Inc., 233 E. Palouse River Dr. P.O. Box 9748, Moscow, Idaho 83843, Phone: (208) 883-4488, Fax: (208) 883-1098, www.Consulting-Foresters.com Acknowledgments This Wildland-Urban Interface Wildfire Mitigation Plan represents the efforts and cooperation of a number of organizations and agencies, through the commitment of people working together to improve the preparedness for wildfire events while reducing factors of risk. Minidoka County Commissioners Mid-Snake Resource Conservation and and the employees of Minidoka County Development USDI Bureau of Land Management USDA Forest Service Idaho Bureau of Homeland Security Federal Emergency Management Agency Minidoka County Fire Protection District West End Fire Protection District Rupert Fire Department & Local Businesses and Idaho Department of Lands Citizens of Minidoka County To obtain copies of this plan contact: Minidoka County Commissioners Office Minidoka County Courthouse 715 G Street, P.O. Box 368 Rupert, ID 83350 Phone: 208-436-7111 Fax: 208-436-0737 Table of Contents CHAPTER I: OVERVIEW OF THIS
    [Show full text]
  • Minidoka National Wildlife Refuge/Lake Walcott State Park
    NORTH MONTANA EAST CENTRAL BOISE SOUTHWEST SOUTHEAST 47 IDAHO BIRDING TRAIL 46 Southeast Region Overview Southeast Region 15 45 47 Pocatello • Idaho Falls EAST CENTRAL 28 43 22 Ashton 44 3 Minidoka National Wildlife Refuge/Lake 1 41 20 32 93 40 53 33 33 42 Walcott State Park Driggs 55 38 22 54 961 E. Minidoka Dam Rd., Rupert • (208) 436-3589 Arco 52 parksandrecreation.idaho.gov/parks/lake-walcott 20 26 39 2 Idaho Falls 51 50 35 36 26 26 15 ebird.org/hotspot/L356665 49 34 37 39 Blackfoot SOUTHWEST 10 11 30 WYOMING LAT/LONG: 42.672615,-113.481555 9 29 34 8 86 25 6 26 14 Pocatello DIRECTIONS: At intersection of ID 24 and ID 25 in the town 7 16 28 5 15 27 31 of Rupert, zero odometer; W on ID 24 (8th St); cross rr 24 3 Soda Springs track; immediate R (N) on A St (Meridian Rd); immediately 86 34 30 32 Burley 12 Rockland 17 15 turn R (NE) again onto ID 24 (Read Ave); follow signs for ID 13 77 18 21 37 24 and Minidoka NWR; mi 5.9 turn R on Minidoka Dam Rd 84 22 23 33 (400 N); drive toward park HQ; mi 11.3 Walcott SP entrance; Malad City 24 56 20 Almo 81 19 89 NWR and SP share common gate; L at fork in rd; L to boat 4 48 ramp, R to NWR. NEVADA UTAH The NWR extends for 25 miles along the Snake River Blackfoot 200 26 from Minidoka Dam and includes all of Lake Walcott.
    [Show full text]
  • Ecological Risk Assessment for the Middle Snake River, Idaho
    United States Office of Research and EPA/600/R-01/017 Environmental Protection Development February 2002 Agency Washington, DC 20460 Ecological Risk Assessment for the Middle Snake River, Idaho National Center for Environmental Assessment—Washington Office Office of Research and Development U.S. Environmental Protection Agency Washington, DC EPA/600/R-01/017 February 2002 ECOLOGICAL RISK ASSESSMENT FOR THE MIDDLE SNAKE RIVER, IDAHO U.S. Environmental Protection Agency National Center for Environmental Assessment-Washington Office Office of Research and Development Washington, DC Office of Environmental Assessment Region 10 Seattle, Washington DISCLAIMER This document has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. ABSTRACT An ecological risk assessment was completed for the Middle Snake River, Idaho. In this assessment, mathematical simulations and field observations were used to analyze exposure and ecological effects and to estimate risk. The Middle Snake River which refers to a 100 km stretch (Milner Dam to King Hill) of the 1,667 km long Snake River lies in the Snake River Plain of southern Idaho. The contributing watershed includes 22,326 square km of land below the Milner Dam and adjacent to the study reach. The demands on the water resources have transformed this once free-flowing river segment to one with multiple impoundments, flow diversions, significant alterations
    [Show full text]